OPTICAL FILTERING IN THE COLLECTION PATH OF A DATA-STORAGE DEVICE

The effects of placing a shading band in the collection path of a magn eto-optical data storage device are presented. The shading band consis ts of an opaque region in the center of the collection aperture, which reduces the low-frequency response of the system without affecting th e high-frequency response. This partially equalizes the system transfe r function. Dynamic measurements indicate that the noise is also reduc ed in the low-frequency region, thus not significantly affecting the n arrow-band carrier-to-noise ratio (CNR). The integrated signal-to-nois e ratio (SNR) shows slight improvement in the high-frequency region.